Packed and Plane Color Support System
Original Publication Date: 1988-Nov-01
Included in the Prior Art Database: 2005-Feb-15
This article describes graphics controller hardware which can support two different data formats: packed color and plane color. These two types of data formats represent color data. In the case of the packed color format, one byte memory address location is used to present one, two, four or eight pels. On the other hand, in the plane color data format, a one-byte memory address location presents eight pels and it has memory banks to represent a color of each pel. Fig. 1 shows a data transfer from the CPU (not shown) to APA memory 10 through graphic controller 12. When the CPU provides the plane color data, multiplexer (MUX) 14 selects the contents of plane mask register 16 in response to a plane color mode signal from the CPU. Plane mask register 16 is used when one or more planes of APA memory 10 are to be masked.